The benefits of road user pricing have been set out in numerous government documents within the UK and other countries. As an alternative to tolls, annual road taxes and fuel duties, road user pricing holds the promise of less traffic congestion, less environmental pollution, greater fairness, safer roads and better use of infrastructure resources.
Road user pricing may command general support, provided the privacy and fairness issues are solved. Privacy relates to the ability of a driver to choose to pay the proper price for a journey without being identified. Fairness relates to the difficulty of a dishonest driver avoiding payment without detection. Cost and environmental considerations may also be issues, particularly the cost and environmental impact of roadside equipment.
Known solutions generally fail to address satisfactorily the privacy, fairness, cost and environmental issues. Typically, such solutions are based on the installation in each vehicle of tamper-proof equipment, usually centered on a smart card issued by or on behalf of the highway authority, which records the journey made by each vehicle. Roadside equipment interacts with the onboard equipment to check that the onboard equipment is operating properly. The driver uploads the information on the smart card in order to be invoiced.
The drawbacks of the above approaches are a) it is not advisable to store data collected from the vehicles under the control of the users of the vehicles and b) the impossibility of tamper-proofing onboard units can lead to fraudulent recording and delayed reporting. A post-paying driver expecting a large bill can “lose” an on board unit smart card. If the charge for losing a card is larger than the maximum cost of the journeys that might have taken place, genuine loss/damage is unfairly penalized.
The deposit on a pre-payment card must be equally large, as a pre-paid on board unit smart card has no way of knowing when it is overspent, but might switch off after a predetermined amount of time or once a certain distance has been recorded.
The benefit of privacy-preserving technologies is severely restricted by the need to process the data pertaining to a vehicle's movement through a charging algorithm in a data centre. Both pre and post-payment methods are affected.
Expensive and intrusive roadside equipment is necessary for enforcement. Equipment must be deployed pervasively before a non-pilot scheme begins. The effectiveness of this approach in detecting evasion is limited.